1. Field of the Invention
The present invention relates to a shield coupling apparatus for implementing a good field of vision and protecting a user""s eyes in a helmet which is designed to protect a user""s head when riding a motorcycle, and in particular to a coupling apparatus for a helmet shield which is capable of preventing a helmet from being upwardly lifted up at a high speed driving of a motorcycle by implementing a slight backward movement of a helmet using a spring when a helmet shield is fully closed in order for a shield to closely contact with a front surface of a helmet, implementing an easier putting-on and putting-off operation of a shield by improving a shield coupling apparatus and maintaining a slightly open state of a shield for thereby preventing a steaming-up phenomenon in the interior of a helmet.
2. Description of the Background Art
Generally, when riding a two-wheeled vehicle such as a motorcycle, etc., a heat protection helmet must be put on for protecting a user""s head. The above helmet includes a shield for implementing a certain field of vision and protecting a user""s eyes.
The above shield of a helmet is coupled to a helmet using a coupling apparatus having hinge portions at both sides for thereby implementing an upward and downward movement of the same. Recently, various helmets having more free upward and downward movements and easier putting-on and putting-off operations are developed.
For an example, according to the Korean Patent Application No. 1999-32362, the Korean Patent Application No. 2000-6348, and the Korean Utility model No. 20-210272, the shield is designed to be tilted upwardly or downwardly. when the shield is tilted, the shield may be stopped at multiple positions, so that a user can determine a tilting angle of the shield. In addition, in the above conventional helmets, the helmet is designed in order for the shield to be easily disassembled from the hinge portion.
However, since the conventional shield coupling apparatus is designed based on only the shield hinge function and the disassembling and assembling structure, the following disadvantages may occur.
Namely, when the shield is fully closed, a certain force is needed in order for the shield to be closely contacted with the helmet. However, in the above conventional helmets, since there is not a certain structure for providing the above. force, the entire portions of the shield may be vibrated or a certain part of the helmet may be slightly lifted-up due to air which collide with a front surface during the driving.
In addition, as shown in FIG. 1, in the case that the helmet includes a protection portion in a jaw portion, a steaming-up phenomenon may occur in an inner surface of the shield due to a user""s breath. In this case, it is impossible to maintain a slightly open state of the shield for the purpose for preventing a steaming-up phenomenon.
Accordingly, it is an object of the present invention to provide a coupling apparatus for a helmet shield which overcomes the problems encountered in the conventional art.
It is another object of the present invention to provide a coupling apparatus for a helmet shield a coupling apparatus for a helmet shield which is capable of preventing a helmet from being upwardly lifted up at a high speed driving of a motorcycle by implementing a slight backward movement of a helmet using a spring when a helmet shield is fully closed in order for a shield to closely contact with a front surface of a helmet, implementing an easier putting-on and putting-off operation of a shield by improving a shield coupling apparatus and maintaining a slightly open state of a shield. for thereby preventing a steaming-up phenomenon in the interior of a helmet.
In order to achieve the above objects, there is provided a coupling apparatus for a helmet shield which includes a helmet, and a shield for closing and opening a front portion of the helmet, comprising a shield which includes left and right protruded inner portion, a curved rim protrusion, a cam shaped shaft portion having an engaging shaft flange at both sides of the rim protrusion, and a guide pin shaft protruded from one side of the same, a movable shaft member which includes a shaft flange guide shoulder portion inserted into the shaft flange of the shield and connected to be rotatable and a locking unit for preventing an escape of the shaft flange, a base member which includes upper and lower escape prevention shoulder portions which are slide-movable by assembling upper and lower escape prevention flanges formed in an outer circumferential surface of the movable shaft member, a concave portion and unlocking member operation space in one side surface, a guide inducing groove for the pin shaft installed in a bottom side of the concave portion, and an unlocking unit for unlocking the locking unit, and a movable shaft member spring which is assembled to the back surface of the base member and includes one end engaged to a spring engaging ring of the movable shaft member and the other end supported by the base member for thereby returning the movable shaft member, wherein the cam shaped shaft portion of the shield is rotatable in the movable shaft member, and the movable shaft member is slide-movable in the concave portion of the base member in the forward and backward direction.